WO 2007/122294 A1 discloses a punching press having a horizontal workpiece support above which a plurality of punching stamps are arranged in rows in a horizontal direction. Above the punching stamps, a stroke drive device which is provided for the punching stamps can be moved along the punching stamp row. Part of the stroke drive device is a ram carriage which can be displaced along the punching stamp row. A ram is movably guided in a vertical direction on the ram carriage. The lower end of the ram faces the punching stamps. At the upper side thereof, the ram is provided with two gear type wedges of a wedge gear. The two gear type wedges are combined to form a structurally unitary wedge arrangement. The wedge arrangement is delimited at the upper side thereof by the wedge faces of the two gear type wedges. The two wedge faces are inclined in opposing directions relative to the horizontal and form at the ram-side wedge arrangement a roof-like dual wedge face. In a vertical direction, a drive-side wedge arrangement is opposite the ram-side wedge arrangement. The drive-side wedge arrangement is also constructed as a structural unit comprising two gear type wedges having wedge faces which are inclined in opposing directions relative to the horizontal and which abut each other in a roof-like manner. Using a motorized spindle drive, the drive-side wedge arrangement can be moved along the punching stamp row and consequently in the displacement direction of the ram carriage. Close to the roof-like dual wedge face, a protrusion protrudes downwards at the drive-side wedge arrangement. A recess on a base plate of the ram-side wedge arrangement is associated with this protrusion. The drive-side protrusion and the ram-side recess can be selectively brought into engagement with each other or out of engagement with each other.
If a selected punching stamp of the punching stamp row is intended to carry out a working stroke for the workpiece processing, and if the ram which is guided on the ram carriage is arranged remote from the selected punching stamp, the ram must first be moved in a horizontal direction into a position in which it is located above the punching stamp which is intended to be actuated by him. To this end, the drive-side wedge arrangement is moved by the motorized spindle drive along the punching stamp row into a position in which the protrusion which protrudes downwards on the drive-side wedge arrangement is arranged opposite of the recess provided in the base plate of the ram-side wedge arrangement. The base plate and also the ram-side wedge arrangement itself are in this instance first lowered in a vertical direction so far that the drive-side protrusion can travel sufficiently far over the base plate of the ram-side wedge arrangement. Subsequently, by a lifting movement of the ram-side wedge arrangement and the base plate thereof, the ram-side recess and the drive-side protrusion are brought into mutual engagement. If the drive-side wedge arrangement is now moved in a motor-driven manner, it carries, via the base plate of the ram-side wedge arrangement, this and the entire ram carriage in the displacement direction. The displacement movement ends as soon as the ram on the ram carriage has reached its desired position above the punching stamp to be actuated. In order to secure the desired position of the ram, the ram carriage is secured on the guide thereof. Subsequently, the ram-side wedge arrangement and the base plate thereof are lowered to such an extent that the protrusion on the drive-side wedge arrangement can leave the recess in the base plate of the ram-side wedge arrangement. Regardless of the lowering movement of the ram-side wedge arrangement and the base plate thereof, the ram is spaced apart as before at its lower side from the punching stamp associated therewith. If the drive-side wedge arrangement is now driven in a motorized manner in the displacement direction thereof, it moves relative to the ram-side wedge arrangement on the ram carriage which is secured in the displacement direction. When the drive-side wedge arrangement moves relative to the ram-side wedge arrangement, owing to the cooperation of the wedge faces at both sides, the ram which is guided in a vertical direction on the ram carriage is moved downwards with a working stroke being carried out. In this instance, the ram acts on the punching stamp opposite it in the vertical direction and this stamp carries out the desired workpiece punching processing operation.